In a case where a power semiconductor device of a self turn-off type, such as an IGBT (Insulated Gate Bipolar Transistor), is used in a drive circuit of a power semiconductor device in the related art, when a voltage fluctuation dV/dt is applied between the collector and the emitter of the power semiconductor device, a gate voltage increases due to a parasitic capacity accompanying the gate of the power semiconductor device. When the gate voltage exceeds a predetermined threshold voltage, the power semiconductor device turns ON erroneously and an arm short-circuit occurs, which gives rise to a problem that the power semiconductor device breaks. In order to avoid this problem, there is a method of applying a negative voltage between the gate and the emitter while the power semiconductor device is in an OFF state. According to this method, however, when a voltage of the voltage fluctuation dV/dt is applied in a state where a power supply voltage of a gate drive circuit is not established, the power semiconductor device may possibly malfunction in a switching operation.
For a drive circuit of self-feeding type that supplies drive power of the semiconductor device from a main circuit of a power converter, there is a method of preventing the semiconductor device from malfunctioning in a switching operation since the main power supply is turned ON until the power supply voltage of the gate drive circuit is established. To be more concrete, a resistor and a P-channel FET (Field Effect Transistor) or an N-channel FET are connected between the gate and the emitter of the semiconductor device in the gate drive circuit. In a case where the gate voltage increases before the power supply voltage of the gate drive circuit rises, an increase of the gate voltage is limited by turning ON the P-channel FET or the N-channel FET. A malfunction of the semiconductor device in a switching operation is thus prevented (see, for example, Patent Document 1)